1. Field of the Invention
The present invention relates to a process for applying a membrane roof cover system (MRCS) containing a polyester foam layer and a new membrane layer over roof deck structure.
2. Description of Related Art
MRCSs are useful for forming a watertight cover over low-sloped roofs. MRCSs can also include an insulation layer, which acts as a thermal insulator, acoustical insulator, or both. Common MRCSs include built-up roof systems (BURS) and flexible sheet membrane (FSM) systems.
BURS typically comprise an insulation layer that goes over a roof deck, a coverboard layer over the insulation layer, and a membrane over the coverboard. The membrane in a BURS generally comprises multiple layers of asphalt, asphalt impregnated fiberglass mat, modified bitumen, or a combination thereof. A FSM system typically comprises an insulation layer over a roof deck and a FSM over the insulation layer.
Membranes on MRCSs can develop cracks as they age, which can result in leaks in the MRCS. Repairing aged MRCSs can involve complete removal of an existing MRCS and application of a new MRCS. An alternative method of repair includes applying a recovery roof system (RRS) over an existing MRCS. RRSs typically include a coverboard to place over a membrane of the existing MRCS and a new membrane layer to go over the coverboard. The coverboard protects the new membrane from debris on the existing MRCS that can abrade and wear the new membrane, leading to a premature failure. Typical coverboards are 4 foot by 8 foot (1.2 meter by 2.4 meter) sheets of fiberboards that are 0.5 inches (1.27 centimeters (cm)) thick. The weight and size of these fiberboards makes their installation labor intensive. Moreover, fiberboards can absorb moisture, which can contribute to roof failures over time.
A process for applying a MRCS either in new roof construction or as a RRS, but that does not require a fiberboard, would be desirable. Of particular interest is such a process that involves simply rolling out a cover material and fastening the cover material to a roof deck.